Marshallia

[7] One species in the genus, Marshallia grandiflora (Appalachian Barbara's buttons) is extinct, having been wiped out in the early 20th century.

That species is found in bogs and scoured riverbanks, and requires periodic flooding to maintain open habitat.

[17] The genus name was given by the botanist Schreber (in Genera Plantarum, 1791) to honor the Marshall family, uncle Humphry and nephew Moses, of Pennsylvania.

The flower heads do resemble buttons, but botanical references giving this name do not quote the Barbara which the name honors (Rickett 1975).

Wells, in Natural Gardens of North Carolina (1932), called the plants "loudspeakers", referring to the megaphone shape of the individual flowers.